UN Secretary General Ban Ki-moon has called on the African Union to speedily provide promised troops to halt the worsening crisis in Central African Republic.
Ban said Friday's resignation of transitional president Michel Djotodia and his prime minister meant speedy action was needed to restore order.
France has sent 1600 troops to Central African Republic to support the African Union force, which is meant to have up to 6000 troops but has not yet reached 3500.
Ban said events in Central African Republic had "gone from bad to worse".
"The 6000 mandated ceiling has not yet been filled and I urge the African Union to expedite this full deployment of these soldiers," the UN chief said at a press conference in New York.
"We must strengthen the African-led mission and do more to prevent the spiral of violence from spreading."
France has called for the deployment of a full peacekeeping mission in Central African Republic.
But diplomats say the African Union has insisted that its force, officially known as MISCA, must be given a chance to halt the strife first.
The African Union has struggled to get contributions of troops and equipment however.
Ban said noted that at least one million people were now displaced in the capital Bangui, where daily killings are still reported.
Ban called it a "terrible crisis".
"There is no functioning government unfortunately. There is a limit for the international community and United Nations when there is no functioning government, no functioning institutions," he said.
